7,722 results
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2. Developing EFL Students’ Multimodal Communicative Competence Through Lady Whistledown’s Society Papers: A Teaching Proposal
- Author
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Beatriz P. Rubio-López
- Subjects
digital communicative competence ,gamification ,multimodality ,remediation ,Education ,Theory and practice of education ,LB5-3640 - Abstract
This paper focuses on integrating multimodal communication into the English-as-a-foreign-language classroom to enhance the development of students’ multimodal communicative competence, multiliteracies, and 21st-century skills. To do so, I compiled a corpus of authentic materials from Lady Whistledown’s Society Papers in Julia Quinn’s novel The Viscount Who Loved Me (2000), her appearances as narrator in the Netflix series Bridgerton (2022), and some tweets posted by @Bridgerton. This corpus was used to plan and design a game-based teaching proposal. Finally, the paper offers a critical analysis and suggests how this proposal can feasibly contribute to fostering students’ multimodal communicative competence.
- Published
- 2024
- Full Text
- View/download PDF
3. Application of OEE for productivity analysis: a case study of a production line from the pulp and paper industry
- Author
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Jairo J .O Andrade and Daniel Dreher Silveira
- Subjects
oee ,quality ,pulp and paper industry ,production process ,Technology ,Mining engineering. Metallurgy ,TN1-997 - Abstract
The overall equipment effectiveness (OEE) is an indicator used in the management and continuous improvement of production systems, and is useful in identifying losses, thus reducing production costs. By analyzing the results of this indicator, the operation manager must make decisions to eliminate or reduce losses in the process. This study investigated the application of the OEE indicator in one production line in the pulp and paper industry. The implementation of OEE was performed in stages with a detailed analysis of the indicators that compose the OEE (quality, performance, and availability) to identify possible improvements. Thus, actions were implemented to improve the OEE quality index. This study provided important information that enabled the operation manager to diagnose and minimize the occurrence of failures and losses, which is often hidden and unknown to those involved in the production system.
- Published
- 2019
- Full Text
- View/download PDF
4. Publication rate and factors associated with the publication of papers submitted to the National Scientific Congresses held by the Peruvian Medical Student Scientific Society between 2010 and 2014
- Author
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Christian Aquino-Canchari, Karla Guillen-Macedo, Yonatan Gómez-Mamani, and Juan Jhonnel Alarco
- Subjects
Medical Students ,Scholarly Communication ,Academic Performance ,Undergraduate Medical Education ,Peru ,Medicine ,Medicine (General) ,R5-920 - Abstract
Introduction: The National Scientific Congress (NSC) is an annual event held in Peru in which medical students from all over the country present their research work. Objectives: To determine the publication rate in indexed scientific journals of research papers submitted to the NSCs held between 2010 and 2014, as well as the factors associated with their publication, and to describe the characteristics of the published papers. Materials and methods: Retrospective study in which 407 abstracts of research papers were reviewed. A publication time window of 6 years (from submission) was considered. A bivariate analysis was performed to assess differences between categorical and numerical variables using the chi-square and Mann-Whitney U tests, respectively. In addition, a multivariate analysis was performed using Poisson regression models (a crude and an adjusted model), calculating relative risk (RR) values with their respective 95% confidence intervals (95%CI) to determine the factors associated with the publication of papers. A significance level of p
- Published
- 2021
- Full Text
- View/download PDF
5. Publication rate and factors associated with the publication of papers submitted to the National Scientific Congresses held by the Peruvian Medical Student Scientific Society between 2010 and 2014.
- Author
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Aquino-Canchari, Christian, Guillen-Macedo, Karla, Gómez-Mamani, Yonatan, and Alarco, Juan Jhonnel
- Subjects
MEDICAL students ,STUDENT organizations ,BIVARIATE analysis ,MANN Whitney U Test ,POISSON regression - Abstract
Copyright of Revista Facultad de Medicina de la Universidad Nacional de Colombia is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
- Full Text
- View/download PDF
6. The technical paper on efficacy and safety of the medical use of cannabis and cannabis-derived finished products is not a systematic review.
- Author
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Ortega-Mora, Gustavo
- Subjects
MEDICAL marijuana - Abstract
The article discusses a technical paper on the medical use of cannabis and cannabis-derived products. The author raises concerns about the paper's methodology and design, suggesting that it is not a systematic review and has several shortcomings. They also argue that the results should be presented in a more easily understandable format. The given document is a list of references related to systematic reviews and overviews of reviews in medicine, providing resources for researchers to improve the quality and efficiency of their reviews. It can be helpful for library patrons conducting research on systematic reviews and evidence-based medicine. [Extracted from the article]
- Published
- 2023
- Full Text
- View/download PDF
7. Physiological quality of jambu (Acmella oleracea) seeds stored in different environments and packages.
- Author
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da Silva, Raquel Santos, de Lima, Michael Ruan Nunes, Dantas Pinto, Matheus Moreira, and Nobre Gama, Juliana Simões
- Subjects
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SEEDS , *PAPER bags , *GERMINATION , *SEED treatment , *PLASTIC bags , *SEEDLINGS - Abstract
Jambu (Acmella oleracea [(L.) RK Jansen]) is a vegetable of great importance in the Amazonian region; it can be found in the daily life of the citizens of the State of Pará (Brazil), since it is part of traditional dishes such as duck in tucupi and tacacá sauce. Although jambu is widely cultivated, agronomic information about its management remains scarce. The aim of the current study was to analyze the physiological potential of jambu seeds stored in different packages and environments. The investigated packages comprised glass, Eppendorf tubes, plastic bags and paper bags conditioned in refrigerator and under natural conditions in Castanhal, Pará, for 360 days. Seed germination, first germination count, emergence seedlings, germination and emergence speed index, and seedling dry weight and length were the variables evaluated at 40-day intervals. The experimental design was completely randomized, with four replicates of 50 seeds per treatment. Jambu seeds were only influenced by the environment where they were stored; the ones stored under natural conditions recorded decreasing behavior for the investigated variables until they reached zero, after 280 storage days. It was possible to conclude that the physiological potential of jambu seeds stored in refrigerator was better conserved. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
8. The_Paper _Money_in_the_Age_of_Cryptographical_Facturation.SRT
- Author
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Beltrán Bohórquez, Nilson and Aguilar Gómez, Diego Andrés
- Subjects
Factura térmica ,775 - Arte computacional (arte digital) [770 - Fotografía, arte computacional, cinematografía] ,Desarrollo económico y social ,Mercado del arte ,Instalación ,Video ,Arte ,Performancia ,Dinero ,Socioeconomic development - Abstract
ilustraciones, graficas La presente escritura versa sobre un proyecto plástico que vincula el lenguaje instalativo como también el del cuerpo a través de acciones que involucran la reflexión sobre el dinero/arte y su carácter reproductible tanto físico como virtual. Investiga la dualidad ficción-realidad del papel moneda en su relación social en términos de su validación. Utiliza como principal soporte el dinero en diferentes dimensiones (cualidad plástica del ecosistema económico): moneda y papel moneda; copias fieles y de baja calidad de dinero de perfil didáctico; facturas y recibos; entre otros. La instalación está dada desde la construcción de máquinas y utilización de diversas tecnologías, así como también del uso de algoritmos y plataformas digitales (ecosistema maquínico). El proyecto interviene, modifica y altera en tiempo real, por medio de máquinas y acciones el soporte plástico (montaje de facturas y recibos), en este sentido, se dirige a una propuesta que se presenta en tiempo real o de forma procesual. Las obras de arte han pasado de una materialidad aural (pictogramas) a una virtualidad profana y desacralizada (NFT), así como el sistema económico en su genealogía pasó del trueque al blockchain. (Texto tomado de la fuente) The present writing is about a plastic project that links the installation language as well as that of the body through actions that involve reflection on money / art and its reproducible nature, both physical and virtual. It investigates the fiction-reality duality of paper money in its social relationship in terms of its validation. It uses money in different dimensions as its main support (plastic quality of the economic ecosystem): money and paper money; lowquality, faithful copies of didactic profile money; invoices and receipts; among others. The installation is given from the construction of machines and the use of various technologies, as well as the use of algorithms and digital platforms (machinic ecosystem). The project intervenes, modifies and alters in real time, by means of machines and actions, the plastic support (assembly of invoices and receipts), in this sense, it is directed to a proposal that is presented in real time or procedurally Facultad de Artes. Universidad Nacional de Colombia Maestría Magíster en Artes Plásticas y Visuales Maestría en Artes Plásticas y Visuales
- Published
- 2021
9. RECIPANEL: RECYCLED PAPER PANELS
- Author
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HERNÁN CAÑOLA, CÉSAR ECHAVARRÍA, and JULIO CÉSAR SÁNCHEZ
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Technology ,Mining engineering. Metallurgy ,TN1-997 - Abstract
En este artículo se estudia la fabricación y el comportamiento mecánico de paneles a base de papel reciclado. El objetivo principal del proyecto es producir un prototipo de panel que emplee elementos provenientes de residuos sólidos (papel periódico) y de un material conglomerante (cemento Portland blanco). El panel debe ser económico, debe tener buenas propiedades mecánicas y debe tener dimensiones comerciales para su uso en muros tabiques y en cielos falsos en la industria de la construcción. El Recipanel es un panel no estructural a base de papel reciclado. El Recipanel cumple las normas colombianas en lo relativo a los paneles de uso no estructural y presenta además unas excelentes características mecánicas.
- Published
- 2012
10. ETHANOL PRODUCTION FROM PAPER SLUDGE USING KLUYVEROMYCES MARXIANUS
- Author
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LINA MARÍA MADRID and JUAN CARLOS QUINTERO DÍAZ
- Subjects
Technology ,Mining engineering. Metallurgy ,TN1-997 - Abstract
El lodo de papel reciclado es una materia prima promisoria para la producción de etanol. En esta investigación, nosotros primero evaluamos el efecto de la concentración de etanol, la carga de sólidos y la cristalinidad de la celulosa sobre la hidrólisis enzimática de la celulosa. También se evaluó la producción de etanol con lodo de papel mediante el proceso de sacarificación y fermentación simultanea (SSF) e hidrólisis y fermentación separada (SHF) empleando la levadura Kluyveromyces marxianus ATCC 36907. El etanol presenta un efecto inhibitorio sobre la hidrólisis de la celulosa. Una concentración de etanol de 40 g/L genera una reducción del 79 % en la producción teórica de azúcares reductores. Al incrementar la concentración de sólidos se observa una reducción en la conversión de la celulosa a azúcares reductores obteniéndose un 76 % de conversión con 9 % de sólidos. Una mayor conversión y productividad en etanol fueron alcanzadas en el proceso SSF en relación al proceso SHF en 72 horas de tratamiento.
- Published
- 2011
11. Storytelling with pictures in childhood: the use of the paper notebook and the electronic notebook in strengthening communication skills in first graders
- Author
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Rodríguez Arango, José Wilson and Castro Barbosa, Sol Mercedes
- Subjects
Technology ,Narration ,Primary school students ,Writing ,Métodos de enseñanza ,Historieta ,Tecnología ,Material didáctico ,Estudiante de primaria ,370 - Educación ,Escritura ,Competencia ,Reading ,Cartoon ,Educational method ,Competence ,Narración ,Teaching materials ,Lectura - Abstract
ilustraciones, fotografías a color, gráficas La presente investigación se desarrolló en el Departamento del Guaviare, municipio San José del Guaviare, Institución Educativa Alfonso López Pumarejo de la zona urbana. El trabajo analiza el uso de las TIC como apoyo al desarrollo de competencias comunicativas, de los niños y niñas en primer grado de básica primaria. Parte de la rememoración visual e imaginaria de los estudiantes a través de las historietas, en su contexto social y cultural. El enfoque de esta investigación es de carácter cualitativo. Se fundamenta en la observación y el análisis de los procesos y prácticas pedagógicas que se aplicaron en el aula de clase con los estudiantes. Por lo tanto, la orientación y el uso adecuado de la tecnología dentro y fuera de las aulas de clase, fortaleció la formación intelectual de los estudiantes de primer grado. El apoyo tecnológico en el proceso de comunicar y escribir, posibilita el aprendizaje significativo en el aula de clase y las historietas, se convierten en eje central del proceso de aprendizaje aplicado en el cuaderno de papel y llevado al cuaderno electrónico. Una experiencia significativa para los estudiantes, los padres participantes y el docente orientador de la investigación. (Texto tomado de la fuente). This research was developed in the Department of Guaviare, San José del Guaviare municipality, Alfonso López Pumarejo Educational Institution in the urban area. The work analyzes the use of ICT to support the development of communicative competences of boys and girls in the first grade of elementary school. Part of the visual and imaginary remembrance of the students through the comics, in their social and cultural context. The focus of this research is qualitative. It is based on the observation and analysis of the pedagogical processes and practices that were applied in the classroom with the students. Therefore, the orientation and proper use of technology inside and outside the classroom, strengthened the intellectual formation of first grade students. Technological support in the process of communicating and writing, enables meaningful learning in the classroom and comics, become the central axis of the learning process applied in the paper notebook and taken to the electronic notebook. A meaningful experience for the students, the participating parents, and the research guiding teacher. Maestría Magíster en Educación Lenguajes y literatura
- Published
- 2021
12. Automatic analysis of textual content of collections of scientific papers to support documentary analysis and knowledge management of a IES in the Colombian Orinoco region
- Author
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Porras García, Yerson Ferney, Cruz-Roa, Angel, González Osorio, Fabio Augusto, MindLab, and Tecnologías Abiertas (GITECX)
- Subjects
Artículos científicos ,Knowledge Management ,Asignación Latente de Dirichlet ,Topic Modeling ,Scientific articles ,Modelado de temas ,Análisis automático de textos ,Indexación automática ,Gestión del conocimiento ,002 - El libro [000 - Ciencias de la computación, información y obras generales] ,Latent Dirichlet Allocation ,Text analysis ,Análisis de texto - Abstract
ilustraciones, diagramas La Universidad de los Llanos (Unillanos), con influencia en la Orinoquía colombiana, ha incrementado la producción de artículos científicos y realizar análisis del contenido textual de generación de nuevo conocimiento empieza a ser tedioso de forma manual. Este trabajo presenta un modelado y análisis automático de temas usando Latent Dirichlet Allocation (LDA) para el análisis semántico y temático de artículos científicos publicados por autores de la Unillanos disponibles en SCOPUS. LDA es comúnmente utilizado para descubrir relaciones de co-ocurrencia entre palabras y conformar grupos con valor semántico latente. Para el análisis, se obtuvo 137 artículos científicos en Inglés, analizados con LDA y usando la medida de desempeño Coherence Measure (CM). Se planteó un proceso sistemático de parámetros para determinar la parametrización del conjunto de datos y modelo LDA. El cual fue evaluado cuantitativa y cualitativamente. Se construyó un instrumento web para el diligenciamiento de las evaluaciones cualitativas por parte de un conjunto de expertos seleccionados, el cual se denominó "whatTopic''. Cuantitativamente, el modelo obtuvo un valor de CM=0.639 para un número de temas de 10. Cualitativamente, se comparó y relacionó temas propuestos con etiquetas preestablecidas por SCOPUS como "Scopus subrea'' y "Scival Topic Prominence''. En ambos casos se identificó como el principal tema la "Experimentación e Investigación'' siendo transversal a los demás temas identificados que están asociados a características de la Unillanos como recursos naturales, agropecuarios, física y telecomunicaciones. (Tomado de la fuente) The Universidad de los Llanos (Unillanos), with influence in the Colombian Orinoco region, has increased the production of scientific articles and the analysis of textual content from generation of new knowledge is difficult when done manually. This paper presents automatic topic modeling and analysis using Latent Dirichlet Allocation (LDA) for the semantic and topic analysis of scientific articles published by authors of Unillanos available in Scopus. LDA is commonly used to discover co-occurrence relationships among words and grouping with latent semantic value. For this analysis, 137 scientific articles in English were obtained, analyzed with LDA, and using the Coherence Measure (CM) as performance measure. A systematic parameter process was proposed to determine the parameterization of the dataset and LDA model. It was evaluated quantitatively and qualitatively. A web-based instrument was constructed for the completion of the qualitative evaluations by a group of selected experts, which was called "whatTopic''. Quantitatively, the model obtained a value of CM=0.639 for a number of topics of 10. Qualitatively, the proposed topics were compared and related to pre-established SCOPUS labels such as "Scopus subrea'' and "Scival Topic Prominence''. In both cases, "Experimentation and Research'' was identified as the main topic, being transversal to the other identified topics associated with Unillanos characteristics such as natural resources, agriculture and livestock, physics and telecommunications. (Text taken from source) Maestría Magíster en Ingeniería - Ingeniería de Sistemas y Computación Computación Aplicada y Ciencias de la Computación
- Published
- 2021
13. 'Sobre quién das cursos? ¿Qué papers escribes?'
- Author
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Antonio Muñoz Molina
- Subjects
Literature (General) ,PN1-6790 - Abstract
Ver documento completo en PDF
- Published
- 2001
14. Application of OEE for productivity analysis: a case study of a production line from the pulp and paper industry
- Author
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Andrade, Jairo J .O, primary and Dreher Silveira, Daniel, additional
- Published
- 2019
- Full Text
- View/download PDF
15. RECIPANEL: RECYCLED PAPER PANELS
- Author
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CAÑOLA, HERNÁN, ECHAVARRÍA, CÉSAR, and SÁNCHEZ, JULIO CÉSAR
- Subjects
Recipanel ,papel reciclado ,recycled paper ,cielo falso ,ceiling ,wall ,muro tabique ,construcción sostenible ,sustainable construction - Abstract
In this paper, the manufacturing and the mechanical behaviour of recycled paper panels are studied. The main goal of this study is to make a prototype panel using recycled paper (newspaper) and white Portland cement. This panel, called Recipanel, must be inexpensive and possess good mechanical properties and commercial dimensions for use in building walls and ceilings. Recipanel is a non-structural panel based on recycled paper and fulfils Colombian regulations for non-structural panels. Recipanel has high mechanical properties. En este artículo se estudia la fabricación y el comportamiento mecánico de paneles a base de papel reciclado. El objetivo principal del proyecto es producir un prototipo de panel que emplee elementos provenientes de residuos sólidos (papel periódico) y de un material conglomerante (cemento Portland blanco). El panel debe ser económico, debe tener buenas propiedades mecánicas y debe tener dimensiones comerciales para su uso en muros tabiques y en cielos falsos en la industria de la construcción. El Recipanel es un panel no estructural a base de papel reciclado. El Recipanel cumple las normas colombianas en lo relativo a los paneles de uso no estructural y presenta además unas excelentes características mecánicas.
- Published
- 2012
16. ETHANOL PRODUCTION FROM PAPER SLUDGE USING KLUYVEROMYCES MARXIANUS
- Author
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MADRID, LINA MARÍA and QUINTERO DÍAZ, JUAN CARLOS
- Subjects
Paper sludge ,Lodo papelero ,fermentación ,etanol ,fermentation, hydrolysis ,Kluyveromyces marxianus ,ethanol ,hidrólisis - Abstract
Recycled paper sludge is a promising raw material for ethanol production. In this study, we first evaluated the effects of ethanol concentration, solids load, and cellulose crystallinity on the enzymatic hydrolysis of cellulose to produce reducing sugars. We then evaluated the production of ethanol by either saccharification and simultaneous fermentation (SSF) or separated hydrolysis and fermentation (SHF) using the yeast Kluyveromyces marxianus ATCC 36907. We found that cellulose hydrolysis decreased as ethanol concentrations increased; at 40 g/L ethanol, the reducing sugar production was decreased by 79 %. Hydrolysis also decreased as solids load increased; at 9 % of solids, the cellulose conversion was 76 % of the stoichiometric production. The ethanol yield and cellulose conversion rate were higher with SSF as opposed to SHF processes at 72 h of treatment. El lodo de papel reciclado es una materia prima promisoria para la producción de etanol. En esta investigación, nosotros primero evaluamos el efecto de la concentración de etanol, la carga de sólidos y la cristalinidad de la celulosa sobre la hidrólisis enzimática de la celulosa. También se evaluó la producción de etanol con lodo de papel mediante el proceso de sacarificación y fermentación simultanea (SSF) e hidrólisis y fermentación separada (SHF) empleando la levadura Kluyveromyces marxianus ATCC 36907. El etanol presenta un efecto inhibitorio sobre la hidrólisis de la celulosa. Una concentración de etanol de 40 g/L genera una reducción del 79 % en la producción teórica de azúcares reductores. Al incrementar la concentración de sólidos se observa una reducción en la conversión de la celulosa a azúcares reductores obteniéndose un 76 % de conversión con 9 % de sólidos. Una mayor conversión y productividad en etanol fueron alcanzadas en el proceso SSF en relación al proceso SHF en 72 horas de tratamiento.
- Published
- 2011
17. The state of the art of marine natural products in Colombia.
- Author
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Bautista, Claudia Andrea, Puentes, Carlos Andrés, Vargas-Peláez, Claudia Marcela, Santos-Acevedo, Marisol, Ramos, Freddy A., Gómez-León, Javier, and Castellanos, Leonardo
- Subjects
MARINE natural products ,MARINE art ,DITERPENES ,NATURAL products ,OCTOCORALLIA - Abstract
Copyright of Revista Colombiana de Química is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
- Full Text
- View/download PDF
18. Publication of works rated as "top ten" at scientific congresses of Peruvian medical students.
- Author
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Aquino-Canchari, Christian, Ticona, Diana Manuela, and Alarco, Juan Jhonnel
- Subjects
MEDICAL students ,MEDICAL schools - Published
- 2022
- Full Text
- View/download PDF
19. Tendencias en la producción de artículos científicos en innovación en el campo de las ciencias administrativas.
- Author
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Pineda-Ospina, Diana Lorena
- Abstract
Copyright of Innovar: Revista de Ciencias Administrativas y Sociales is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
- Full Text
- View/download PDF
20. Publication of works presented in the 2016 and 2018 editions of the National Student Scientific Event on Internal Medicine -MEDINTÁVILA.
- Author
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Hernández-García, Frank, Corrales-Reyes, Ibraín Enrique, Pérez-García, Enrique Rolando, Sorí-Peña, Juan Antonio, Góngora-Gómez, Onelis, and Mejia, Christian Richard
- Subjects
INTERNAL medicine ,BIVARIATE analysis ,SCIENCE students ,SCIENCE publishing ,JOB descriptions - Abstract
Copyright of Revista Facultad de Medicina de la Universidad Nacional de Colombia is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
- Full Text
- View/download PDF
21. Dryer design parameters and parts specifications for an industrial scale bagasse drying system
- Author
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Alexander Larsen, Jarrod Dwyer, Greg Wheatley, Rong Situ, and Robiul Islam Rubel
- Subjects
Moisture content ,Moisture ,Sugar industry ,Boiler (power generation) ,Soil Science ,Industry by-product ,04 agricultural and veterinary sciences ,Drying tube ,Pulp and paper industry ,040401 food science ,Cogeneration ,0404 agricultural biotechnology ,Electricity generation ,Electricity cogeneration ,040103 agronomy & agriculture ,0401 agriculture, forestry, and fisheries ,Environmental science ,Contenido de humedad ,Subproducto de la industria ,Bagasse ,Tonne ,Agronomy and Crop Science ,Water content ,Industria azucarera ,Cogeneración de electricidad - Abstract
The sugar industry is an ideal sector for electricity cogeneration due to a large amount of burnable bagasse produce as a by-product. Bagasse produced in the sugar industry always consists of moisture affecting the efficiency of a boiler in the cogeneration plant. In our case study, a cogeneration plant run by bagasse burning found with bagasse moisture problem and suffocating with low power generation for the last few years. The boiler efficiency per tonne of bagasse is currently lower than optimal due to the substantial percentage of water present in the bagasse. A bagasse dryer design for this industry can improve the efficiency of a boiler as well as the cogeneration plant. In this paper, a pneumatic bagasse drying system is proposed to reduce the moisture content of bagasse from 48% to 30%. This work provides a full analysis of bagasse dryer design parameters, including specifications for dryer system components, such as feeders, fan, drying tube, and cyclone. The total bagasse drying system proposed is expected to be fitted within a 6 x 6 x 25 m space to dry 60 tph of bagasse, reducing the moisture content from 48% to 30%, in full compliance with all relevant Australian and company standards. Resumen La industria azucarera es un sector ideal para la cogeneración eléctrica debido a la gran cantidad de bagazo que se produce como subproducto. El bagazo producido en la industria azucarera siempre consiste en humedad que afecta la eficiencia de una caldera en la planta de cogeneración. En nuestro caso de estudio, una planta de cogeneración operada por la quema de bagazo se encontró con un problema de humedad del bagazo y asfixiada con baja generación de energía durante los últimos años. La eficiencia de la caldera por tonelada de bagazo es actualmente inferior a la óptima debido al porcentaje sustancial de agua presente en el bagazo. Un diseño de secador de bagazo para esta industria puede mejorar la eficiencia de una caldera y de la planta de cogeneración. En este trabajo, se propone un sistema de secado neumático de bagazo para reducir el contenido de humedad del bagazo del 48% al 30%. Este trabajo proporciona un análisis completo de los parámetros de diseño del secador de bagazo, incluidas las especificaciones de los componentes del sistema del secador, como alimentadores, ven tiladores, tubos de secado y ciclones. Se espera que el sistema de secado total de bagazo propuesto se instale en un espacio de 6 x 6 x 25 m para secar 60 tph de bagazo, reduciendo el contenido de humedad del 48% al 30%, en total cumplimiento con todas las normas relevantes de Australia y de la empresa.
- Published
- 2021
22. Influence of fractional distillation on the yield and quality of biofuels obtained through thermal catalytic cracking of crude palm oil
- Author
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Nélio T. Machado Nélio, Andréia A. M. Mota Andréia, and Silvio Alex P. Mota Silvio
- Subjects
Fractional distillation ,Vegetable oil refining ,General Engineering ,Pulp and paper industry ,Fluid catalytic cracking ,law.invention ,Diesel fuel ,chemistry.chemical_compound ,chemistry ,law ,Biofuel ,Environmental science ,Petroleum ,Gasoline ,Distillation - Abstract
This paper investigates the influence of the fractional distillation on the yield and quality of biofuels obtained in a laboratory unit (Vigreux column) at atmospheric pressure, producing three distilled fractions: (1) green gasoline, (2) green aviation kerosene, and (3) green diesel. The quality of the distilled fractions was evaluated through physical-chemical analysis, FTIR spectroscopy, and GC-MS analysis. The fractional distillation of the crude biofuel provided biofuels in the form of distilled fractions with most values of physical-chemical properties within the limits established by national and international regulatory agencies and with experimental distillation curves similar to standard distillation curves. GC-MS analysis showed that the three distilled fractions had higher contents of hydrocarbons than oxygenated compounds and contained hydrocarbons characteristic of petroleum derivatives such as gasoline, aviation kerosene, and diesel.
- Published
- 2021
23. Aplicación del OEE para análisis de la productividad: un estudio de caso aplicado en una línea de producción en una industria de pulpa y papel
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Jairo José de Oliveira Andrade and Daniel Dreher Silveira
- Subjects
lcsh:TN1-997 ,Production line ,OEE ,proceso de producción ,oee ,lcsh:T ,Computer science ,Process (engineering) ,media_common.quotation_subject ,calidad ,General Engineering ,industria de pulpa y papel ,Pulp and paper industry ,lcsh:Technology ,Overall equipment effectiveness ,pulp and paper industry ,quality ,Production (economics) ,Quality (business) ,Productivity ,lcsh:Mining engineering. Metallurgy ,production process ,Production system ,media_common - Abstract
The overall equipment effectiveness (OEE) is an indicator used in the management and continuous improvement of production systems, and is useful in identifying losses, thus reducing production costs. By analyzing the results of this indicator, the operation manager must make decisions to eliminate or reduce losses in the process. This study investigated the application of the OEE indicator in one production line in the pulp and paper industry. The implementation of OEE was performed in stages with a detailed analysis of the indicators that compose the OEE (quality, performance, and availability) to identify possible improvements. Thus, actions were implemented to improve the OEE quality index. This study provided important information that enabled the operation manager to diagnose and minimize the occurrence of failures and losses, which is often hidden and unknown to those involved in the production system. Resumen La Eficacia Global del Equipo (OEE) es un indicador utilizado como una forma de gestión y mejora continua de los sistemas y equipos de producción, útil para identificar las pérdidas, reduciendo así los costos de producción. Al analizar los resultados de este indicador, el gerente de operación debe tomar decisiones que apuntan a la mejor manera de eliminar o reducir las pérdidas en el proceso. Con el fin de analizar en detalle la aplicación del indicador OEE en uno de los sistemas de producción de una empresa del sector de pulpa y papel, se realizó un estudio de caso. La implementación del OEE se llevó a cabo en etapas, con un análisis detallado de los indicadores que conforman el OEE (calidad, desempeño y disponibilidad), con el fin de identificar posibles puntos de mejora. Después de los análisis, se implementaron acciones para mejorar el índice de calidad de OEE. El estudio proporcionó información importante para que el gerente de operación pudiera tomar medidas para diagnosticar y minimizar la ocurrencia de fallas y pérdidas, a menudo ocultas y desconocidas para aquellos involucrados en el sistema de producción.
- Published
- 2019
24. Some Improved Combined Estimators of Population Mean in Stratified Ranked Set Sampling.
- Author
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SINGH, RAJESH and KUMARI, ANAMIKA
- Abstract
Copyright of Colombian Journal of Statistics / Revista Colombiana de Estadística is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
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25. Sobre a arte como fotografia em Mário de Andrade e Walter Benjamin.
- Author
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Schmitz Kremer, Natan and Fernandez Vaz, Alexandre
- Subjects
MODERNITY - Abstract
Copyright of Literatura: Teoría, Historia, Crítica is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
26. La universalización de la pensión no contributiva en los adultos mayores en México en el sexenio 2018-2024: un análisis preliminar de sus efectos en la pobreza.
- Author
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Rodríguez-Gómez, Katya
- Abstract
Copyright of Revista FORUM is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
27. Unit Regression Models to Explain Vote Proportions in the Brazilian Presidential Elections in 2018.
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Guerra, Renata Rojas, Peña-Ramírez, Fernando A., Ribeiro, Tatiane Fontana, Cordeiro, Gauss M., and Mafalda, Charles Peixoto
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PRESIDENTIAL elections ,REGRESSION analysis ,RUNOFF elections ,VOTING ,CITIES & towns ,PER capita - Abstract
Copyright of Colombian Journal of Statistics / Revista Colombiana de Estadística is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
28. Two-Step Calibrated Designed Weighted Estimators of Finite Population Variance for a Mailed Survey Design Characterized by Non-response.
- Author
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Audu, A., Lekganyane, M., Ishaq, O. O., and Aremu, K. O.
- Subjects
NONRESPONSE (Statistics) ,MEAN square algorithms ,EXTREME value theory ,STATISTICAL sampling ,VARIANCES ,DESIGN techniques - Abstract
Copyright of Colombian Journal of Statistics / Revista Colombiana de Estadística is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
29. New Unconditional and Quantile Regression Model Erf-Weibull: An Alternative to Gamma, Gumbel and Exponentiated Exponential Distributions.
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Carneosso, Caroline Cogo, De Andrade, Thiago A. N., and Bisognin, Cleber
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QUANTILE regression ,DISTRIBUTION (Probability theory) ,REGRESSION analysis ,WEIBULL distribution ,ERROR functions ,GAUSSIAN function - Abstract
Copyright of Colombian Journal of Statistics / Revista Colombiana de Estadística is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
30. Compuestos fenólicos y actividad antioxidante in vitro de seis accesiones de mashua (Tropaeolum tuberosum R. & P.) de la Región Puno, Perú
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Ivan Best, Haim Behar, Oscar Reategui, Danae Liviac, and Jesús Arcos
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Polifenoles ,Antioxidant ,DPPH ,medicine.medical_treatment ,Antioxidantes ,Horticulture ,engineering.material ,Antioxidants ,Rutin ,chemistry.chemical_compound ,Nutraceutical ,Tropaeolum tuberosum ,Tubéculos vegetales ,medicine ,Caffeic acid ,Food science ,Flavonoides ,Flavonoids ,biology ,Pulp (paper) ,purl.org/pe-repo/ocde/ford#4.04.02 [https] ,Polyphenols ,food and beverages ,Forestry ,biology.organism_classification ,Plant tubers ,chemistry ,Polyphenol ,engineering ,Animal Science and Zoology ,HPLC ,Agronomy and Crop Science ,Food Science - Abstract
Mashua (Tropaeolum tuberosum R. & P.) is an Andean crop of high nutritional value and medicinal properties, which presents a great diversity in morphology and color. The aim of the study was to evaluate the content of phenolic compounds and in vitro antioxidant activity of the most economically important mashua accessions in the Puno Region, Peru. Six accessions of mashua (three purple-colored and three yellow-colored) were evaluated. The content of total polyphenols, total flavonoids and identification of phenolic compounds was determined by the Folin-Ciocalteu assay, aluminum chloride colorimetric method and HPLC-DAD, respectively. In vitro antioxidant activity was evaluated using the FRAP and DPPH assays. In general, the purple-colored mashua had a significantly higher content of total polyphenols, total flavonoids, and in vitro antioxidant activity compared to the yellow-colored mashua; being the Tt-23 accession purple-colored (peel/pulp, purple/purple), which presented a significantly higher content of phenolic compounds and in vitro antioxidant activity compared to the other accessions evaluated (P
- Published
- 2021
31. Characterization Physico-chemical and mechanical of 4 vegetable fibers used as artisanal raw materials in the Department of Nariño
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Juliana Chamorro Mejía, Laura De la Cruz Velasco, and Carlos Córdoba-Cely
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Textile industry ,biology ,business.industry ,Carludovica palmata ,General Engineering ,Fique ,Schoenoplectus californicus ,Raw material ,biology.organism_classification ,Pulp and paper industry ,Characterization (materials science) ,Vegetable fibers ,Environmental science ,business - Abstract
Nowadays there is very little information about the properties of the main vegetable fibers used in artisanal production in southern Colombia. The present comparative study analyzes the physical-chemical and mechanical properties of Fique (Furcraea macrophylla), Tetera (Stromanthe stromathoides or Stromanthe jacquinii), Totora (Schoenoplectus californicus) and Iraca or Toquilla Palm (Carludovica palmata), with the intention of identifying its strengths and weaknesses like an artisan raw material. The study found that fibers with higher elasticity such as Fique can be used for items such as clothing, while stronger fibers such as Tetera can be used to create items such as baskets that require more resistance to weight and rigidity. It was also found that Iraca and Totora could be better applied in the textile industry, and that the high moisture content in all fibers can affect their technological characteristics and the quality life cycle of artisan products.
- Published
- 2021
32. El estudio de las organizaciones en economías informales: conceptos, antecedentes y perspectivas futuras.
- Author
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Vanegas-Chinchilla, Nórida, González Salazar, Natalia, and Montoya Hernández, Angela
- Abstract
Copyright of Innovar: Revista de Ciencias Administrativas y Sociales is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
- View/download PDF
33. Organizaciones de lucha social surgidas en el estallido social en Cali: repensando la organización.
- Author
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Milec Cifuentes-Leiton, Diana, Rojas-Rojas, William, Otálvaro Marín, Bairon, and Fernando Cruz-Rincón, Diego
- Abstract
Copyright of Innovar: Revista de Ciencias Administrativas y Sociales is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
- View/download PDF
34. Evaluación experimental y económica de un electrolizador alcalino para operación dual en motores diésel de baja cilindrada
- Author
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Brando Hernández, Jorge Duarte Forero, and Daniel Maestre-Cambronel
- Subjects
Materials science ,Hydrogen ,Alkaline water electrolysis ,General Engineering ,chemistry.chemical_element ,Electrolyte ,Pulp and paper industry ,Diesel engine ,economic analysis ,fuel consumption ,Diesel fuel ,motor diésel ,chemistry ,hydrogen ,Fuel efficiency ,Hydrogen fuel enhancement ,consumo de combustible ,electrolizador alcalino ,alkaline electrolyzer ,análisis económico ,hidrógeno ,Hydrogen production ,diesel engine - Abstract
This investigation evaluated the integration of an alkaline electrolyzer for dual-fuel operation in an experimental test bench of a diesel engine from a techno-economic viewpoint. The characterization of the electrolyzer operation indicated that higher electrolyte (KOH) concentrations (30 - 40% w/w) improve the overall performance since less voltage is required for electrolysis, thus featuring higher efficiencies (50 - 60%) and hydrogen production (4 - 6 LPM). The economic analysis demonstrated that hydrogen cost remains competitive (4.3 - 5.6 USD/kg), and it is greatly dependent on the electrolyte concentration. Additionally, the operation of the engine with hydrogen injection at 20 LPM and a palm biodiesel blend reduced the fuel consumption rate between 10 - 31% depending on the load rate when compared to pure diesel. In contrast, dual-fuel operation generated a minor reduction in fuel conversion efficiency (< 5%), which reflects on the power output. Overall, this technology stands as a promising avenue to improve the fuel utilization ratio. Resumen Esta investigación evaluó la integración de un electrolizador alcalino para la operación con combustible dual en un banco de pruebas experimental de un motor diésel desde un punto de vista tecno-económico. La caracterización de la operación del electrolizador indicó que concentraciones más altas de electrolitos (KOH) (30 - 40% p/p) mejoran el rendimiento general, ya que se requiere menos voltaje para la electrólisis, lo que presenta mayores eficiencias (50 - 60%) y producción de hidrógeno (4 - 6 LPM). El análisis económico demostró que el costo del hidrógeno sigue siendo competitivo (4.3 - 5.6 USD/kg) y depende en gran medida de la concentración de electrolitos. Además, el funcionamiento del motor con inyección de hidrógeno a 20 LPM y una mezcla de biodiesel de palma redujo la tasa de consumo de combustible entre un 10 - 31% dependiendo de la tasa de carga, en comparación con el diésel puro. Por el contrario, el funcionamiento con combustible dual generó una reducción menor en la eficiencia de conversión de combustible (< 5%), lo que se refleja en la potencia de salida. En general, esta tecnología se presenta como una vía prometedora para mejorar el índice de utilización de combustible.
- Published
- 2022
35. Heuristic methods for teaching-learning concepts associated with the development of spatial reasoning with architecture students
- Author
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Tinoco Robledo, Luz Elena, Dorado Correa, Ivon Andrea, Tinoco Robledo, Luz Elena [0000-0001-5250-3839], Tinoco Robledo, Luz Elena [https://scienti.minciencias.gov.co/cvlac/visualizador/generarCurriculoCv.do?cod_rh=0001688394], and Tinoco Robledo, Luz Elena [Luz_Elena_Tinoco_Robledo]
- Subjects
Operative design ,Transformaciones isométricas ,Architectural drawing ,Isomorphic transformations ,Diseño arquitectónico ,Architectural design ,Métodos heurísticos ,Paper folding ,Isometric transformations ,Pentominoes ,Ordering principles ,Razonamiento espacial ,Dibujo arquitectónico ,Pentominó ,Crease patterns ,Heuristic methods ,Papiroflexia ,Patrones de plegado ,Transformaciones isomorfas ,Operaciones de diseño ,Principios ordenadores ,Spatial reasoning - Abstract
ilustraciones, fotografías En esta investigación se trabaja alrededor de los métodos heurísticos que usan estudiantes de Arquitectura en situaciones problema involucrando nociones de perímetro, área, volumen, y las transformaciones isométricas e isomorfas. Esta investigación, bajo la metodología basada en diseño, buscó relacionar parte de los procesos de diseño compositivo con respecto a las nociones de geometría, buscando fortalecer la argumentación en estos procesos, desde la interpretación de la Arquitectura como forma y función. En los resultados se evidencian las nociones de geometría inherentes a los procesos de composición en diseño, las formas en las que los estudiantes resuelven situaciones problema a través del uso de material tangible como pentominó y papiroflexia, y finalmente, el aporte en el razonamiento espacial. Así se establece una relación entre los elementos que integran esta investigación: la matemática y la arquitectura desde sus propias disciplinas, el material tangible como el medio para proponer situaciones problema y los métodos heurísticos como el enfoque que potencia el razonamiento espacial. (texto tomado de la fuente) This research focuses on heuristic methods used by Architecture’s students in problem situations involving notions of perimeter, area, volume, and isometric and isomorphic transformations. The research, under the design-based methodology, aimed to relate part of the compositional design processes with respect to the notions of geometry, in order to improve the argumentation within these process using the interpretation of Architecture both as a form and a function. The results show the notions of geometry inherent to the processes of composition in design, the ways in which students solve problem situations through the use of tangible materials such as pentominoes and origami, and finally, the way in which their spatial reasoning is developed. Thus, a relationship is established between the elements that integrate this research: mathematics and architecture, from their own disciplines, tangible material as the tools to propose problem situations and heuristic methods, as the approach that enhances spatial reasoning. Maestría
- Published
- 2022
36. Actividades enzimáticas significativas en la hidrólisis de residuos de la cosecha de caña de azúcar
- Author
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Luz Marina Flórez Pardo, Jorge Enrique López Galán, Jairo Salcedo Mendoza, and Universidad Nacional de Colombia, Sede Medellín
- Subjects
0301 basic medicine ,lcsh:TN1-997 ,Crop residue ,Sugar cane ,sugar cane ,Hidrólisis enzimática ,01 natural sciences ,lcsh:Technology ,03 medical and health sciences ,chemistry.chemical_compound ,Hydrolysis ,top cane ,Caña de azúcar ,Hidrolisis ,Food science ,Cane ,lcsh:Mining engineering. Metallurgy ,chemistry.chemical_classification ,Hemicelulasas ,Ethanol ,Tallo ,Filter paper ,biology ,Chemistry ,lcsh:T ,010401 analytical chemistry ,Celulasas ,General Engineering ,enzymatic hydrolysis ,hemicellulose ,cellulases ,biology.organism_classification ,0104 chemical sciences ,hemicelulasas ,030104 developmental biology ,Enzyme ,Hojas ,Degradation (geology) ,leaves - Abstract
In the production of ethanol from agroindustrial crop residues, one of the critical stages in the process is the conversion of lignocellulosic material to simple sugars, which can be done chemically or enzymatically. In this research, the enzymatic activities of commercial enzymes were evaluated for their influence on the degradation of lignocellulosic materials from sugar cane harvest residues (leaves and top cane). Eight substrates were pretreated with different delignification methods. Likewise, five enzymatic preparations were configured. An analysis of the enzyme-substrate interactions was conducted through fuzzy system analysis. The results showed regions of maximum enzymatic activity for residues of the sugarcane harvest, between 20-30 Filter Paper Units (FPU) /mL values lower than 500 pNPG (p-Nitrofenol-α-D-Glucopyranoside) U / mL of activity beta-glucosidase and hemicellulase activity between 50 and 70 IU / mL, confirming that the use of large amounts of cellulolytic enzymes is not necessary. Resumen En la producción de etanol a partir de residuos agroindustriales, una de las etapas críticas en el proceso es la conversión del material lignocelulósico a azúcares simples, que puede realizarse química o enzimáticamente. En esta investigación, se evaluó la influencia de las actividades enzimáticas de las enzimas comerciales para degradar materiales de residuos de cosecha de la caña de azúcar (hojas y cogollos). Ocho sustratos fueron pretratados con diferentes métodos de deslignificación, con cinco preparaciones enzimáticas. Se utilizó un análisis de las interacciones enzima-sustrato, a través del análisis del sistema difuso. Los resultados mostraron regiones de actividad enzimática entre 20-30 FPU / mL y valores inferiores a 500 pNPG U / mL de actividad beta-glucosidasa y para actividad hemicelulasa entre 50 y 70 IU / mL, confirmando que el uso de grandes cantidades de enzimas celulolíticas no es necesario.
- Published
- 2019
37. Composting of byproducts from the orange (Citrus sinensis (L.) Osbeck) and sugarcane (Saccharum spp. hybrids) agroindustries
- Author
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Teresita de Jesús Debernardi-Vázquez, Rosalía Núñez-Pastrana, and Noé Aguilar-Rivera
- Subjects
chemistry.chemical_classification ,Compost ,020209 energy ,Biofertilizer ,General Engineering ,02 engineering and technology ,Building and Construction ,Biodegradable waste ,010501 environmental sciences ,engineering.material ,Pulp and paper industry ,01 natural sciences ,Fodder ,chemistry ,Biofuel ,Bioproducts ,0202 electrical engineering, electronic engineering, information engineering ,engineering ,Environmental science ,Organic matter ,Citrus × sinensis ,0105 earth and related environmental sciences - Abstract
There is a global problem involving the generation, management, disposal, and treatment of agro-industrial waste, since it requires technologies for its transformation into the sustainable production of food, fodder, biofuels, fibers, bioproducts, and biofertilizers. The citrus and sugarcane agroindustries generate waste or byproducts that require a special treatment to be reused. Sugarcane byproducts already have an established but unsustainable use. In the case of citrus fruits, 50-60% of the organic waste has an acidic pH (3-4), 95% organic matter, and 80-90% moisture. The objective of this research was to evaluate and model the pile composting method applied to byproducts of the orange and sugarcane agroindustries to obtain compost with competitive physicochemical parameters for use as a soil improver. The pile was designed with a pyramidal rectangular arrangement, and 9 points were established for temperature sampling in three different sections during composting. An average of 55 °C and a pH of 9,1 were obtained at the end of the process. Compared to the regional control, the C/N ratio (27,5), organic matter (65,5%), and macro- and microelements show improved characteristics for use in food production in agroecological agriculture.
- Published
- 2020
38. Obtaining bioproducts by slow pyrolysis of coffee and cocoa husks as suitable candidates for being used as soil amendment and source of energy
- Author
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Mónica Hernández-Rodríguez, José Falcón-Hernández, Alexis Otero-Calvis, and Lorelis Milian-Luperón
- Subjects
020209 energy ,Amendment ,Biomass ,energy potential ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Husk ,lcsh:Chemistry ,Yield (wine) ,Bioproducts ,gas ,Biochar ,0202 electrical engineering, electronic engineering, information engineering ,0105 earth and related environmental sciences ,bio-char ,business.industry ,General Chemistry ,Pulp and paper industry ,slow pyrolysis ,Renewable energy ,lcsh:QD1-999 ,bio-oil ,Environmental science ,business ,Pyrolysis - Abstract
The agricultural economic policy of Cuba pretends to triplicate the crops of coffee and cocoa by 2021, a measure which will bring about both an increase in biomass waste and the need to find a proper method for its disposal. Slow pyrolysis process can transform lignocellulosic waste into added value products as biochar, bio-oil and gas. The present research evaluated the yield and the theoretical potential energy of co-products (biochar, bio-oil, and gas) from coffee and cocoa seed husks using the pyrolysis process as a source of friendly and renewable energy. Results indicated that coffee husks are more suitable for the production of gas with a yield of 40.4%, while cocoa seed husks are better suited for the production of bio-oil, with a yield of 37.4%. For 2021 the theoretical energy potential estimated is 8291 MWh, equivalent to 716000 kg for the coffee husks, and 1384 MWh equivalent to 121000 kg for the cocoa seed husks. The bio-char characterization indicated high contents of carbon, calcium, potassium, nitrogen, and oxygen, which makes it a suitable candidate for being used as a soil amendment. The conversion of coffee and cocoa seed husks into added value products through slow pyrolysis process will help clean the environment, decrease the greenhouse effect, and will aid farmers in the rural populations by providing them with an additional source of income.
- Published
- 2020
39. Caracterización por colorimetría de accesiones de plátano del Sistema de Bancos de Germoplasma en Colombia
- Author
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Luis Eduardo Ordóñez-Santos, Alvaro Caicedo-Arana, Eberto Rodriguez-Henao, and Ayda Lilia Enriquez-Valencia
- Subjects
Color superficial ,Germplasm Bank ,Soil Science ,Constant speed ,Colombia ,engineering.material ,01 natural sciences ,010309 optics ,polifenol oxidase ,0404 agricultural biotechnology ,polifenol oxidasa ,0103 physical sciences ,Chromaticity ,recursos genéticos ,Mathematics ,Hue ,browning ,biology ,Color difference ,pardeamiento ,Pulp (paper) ,Musa balbisiana ,superficial color ,04 agricultural and veterinary sciences ,biology.organism_classification ,040401 food science ,Musaceae ,genetic resources ,Horticulture ,engineering ,Agronomy and Crop Science - Abstract
Resumen El color es uno de los atributos sensoriales que mejor define la calidad de un alimento, no obstante las investigaciones sobre el color superficial de pulpa de frutos de musáceas en Colombia son escasas. Esta información es de gran utilidad para identificar materiales promisorios destinados para consumo fresco y procesamiento agroindustrial. En este estudio se caracterizó el color superficial de la pulpa de 25 accesiones de plátano Musa sp. (Musaceae) del Banco de Germoplasma de Musáceas del Sistema de Bancos de Germoplasma de la Nación para la Alimentación y la Agricultura (SBGNAA) existente en la Corporación Colombiana de Investigación Agropecuaria (Agrosavia) en Palmira, Colombia. Las coordenadas CIEL.a.b. fueron determinadas por triplicado utilizando un colorímetro, entre ellas se calcularon parámetros de cromaticidad (C*), tonalidad (h°) y diferencia de color (AE). Las accesiones de plátano presentaron rangos de L*(17.31-79.30), a*(8.73-30.64). y b*(15.24-95.49), C*(17.77-98.22), h°(38.24-81.00) y AE*(147.07-6851.24). Las pulpas de plátano fueron clasificadas colorimétricamente entre amarillos tenues a amarillos intensos. La variación de las coordenadas colorimétricas a*, h°, y AE se ajustaron a una cinética de orden cero; y L*, b* y C* describieron una cinética de primer orden. Las accesiones Benedetta, Cachaco espermo, Cachaco sin bellota, Dominico mocho, Dominico mutante, GAEP-2, Hartón tigre y Maia Maoli Risaralda, fueron clasificadas como materiales promisorios para consumo en fresco o procesos agroindustriales, por los bajos valores de la constante de velocidad cinética (k) registrados en el presente estudio. Abstract Color is one of the sensory attributes that best define the quality of a food, however, to date there are no scientific investigations that record the study of superficial color of the fruit pulp of Musaceae, which provides useful information to identify promising materials destined for fresh consumption and agroindustrial processing. Surface color of plantain, Musa sp. (Musaceae) pulp from the Musaceae Germplasm Bank of the Corporación Colombiana de Investigación Agropecuaria (Agrosavia) was characterized. The CIEL.a.b. coordinates of the pulp of 25 plantain accessions were determined in triplicate using a colorimeter. From the coordinates of the surface color, parameters of chromaticity (C*), hue (h°), and color difference (ΔE) were calculated. Plantain accessions presented a range of L* (17.31-79.30), a* (8.73-30.64), and b* (15.24-95.49), C* (17.77) -98.22), h° 38.24-81.00) and ΔE* (147.07-6851.24). The plantain pulps can be classified colorimetrically among mild to intense yellows. Variation of the colorimetric coordinates a*, h°, and ΔE were adjusted to zero-order kinetics, and L*, b* and C* described a first-order kinetics. Accessions Benedetta, Cachaco espermo, Cachaco sin bellotae, Dominico mocho, Dominico mutant, GAEP-2, Hartón tigre and Maia Maoli Risaralda, are reported as promising materials for fresh consumption or agroindustrial processes, due to the low values of the constant speed kinetics (k) recorded in the present study.
- Published
- 2020
40. Enriquecimiento de la matriz biológica cidra Sechium edule (Jacq.) Sw. con Lactobacillus casei y saborizada con maracuyá Passiflora edulis L
- Author
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Clara María Mejía Doria, Francisco Fernei Obando Mejia, and Alba Lucia Duque Cifuentes
- Subjects
Lactobacillus casei ,biology ,Chemistry ,020209 energy ,Microorganism ,Pulp (paper) ,0211 other engineering and technologies ,General Engineering ,Titratable acid ,02 engineering and technology ,engineering.material ,biology.organism_classification ,law.invention ,Lactic acid ,Probiotic ,chemistry.chemical_compound ,law ,021105 building & construction ,0202 electrical engineering, electronic engineering, information engineering ,engineering ,Food science ,Passion fruit ,Flavor - Abstract
Los probióticos son bacterias ácido-lácticas que mejoran el equilibrio microbiano. El objetivo de esta investigación fue enriquecer la matriz cidra con Lactobacillus casei y saborizarla con maracuyá. Se determinó la porosidad y se realizó impregnación a vacío a geometrías de cidra con formulaciones de maracuyá; las muestras de cidra se caracterizaron fisicoquímicamente. Se realizó el enriquecimiento con Lactobacillus casei con 109 UFC/mL y se evalúo la viabilidad de los microorganismos. Los resultados mostraron valores similares de porosidad en paralelepípedos y láminas (0,995±0,003 y 0,991±0,005, respectivamente); mientras que los ºBrix (9,9±0,12 y 10,2±0,12) y el pH (6,03±0,01 y 6,06±0,01) fueron mayores en láminas; la acidez titulable (0,301±0,012 y 0,258±0,012) fue mayor en paralelepípedos, presentaron mayor viabilidad después de 20 días de almacenamiento con valores superiores a 106 UFC/g y mayor aceptación sensorial. La formulación 75:25 pulpa:agua y la geometría en paralelepípedos presentaron las condiciones más adecuadas para la incorporación del probiótico.
- Published
- 2020
41. Growth of Desmodesmus subspicatus green microalgae and nutrient removal from sugarcane vinasse clarified by electrocoagulation using aluminum or iron electrodes
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Reinaldo Gaspar Bastos, Viktor Oswaldo Cárdenas Concha, Flávia Paschino Bissoto, Roniel Augusto de Souza, and Mauricio Daniel Montaño Saavedra
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lcsh:TN1-997 ,cultivo mixotrófico ,Vinasse ,Biomass ,Context (language use) ,02 engineering and technology ,010501 environmental sciences ,Raw material ,01 natural sciences ,complex mixtures ,lcsh:Technology ,mixotrophic growth ,efluente de destilaría ,Ethanol fuel ,Effluent ,lcsh:Mining engineering. Metallurgy ,0105 earth and related environmental sciences ,Chemistry ,lcsh:T ,General Engineering ,021001 nanoscience & nanotechnology ,Pulp and paper industry ,wastewater treatment ,Wastewater ,Biofuel ,distillery effluent ,0210 nano-technology ,tratamiento de aguas residuales - Abstract
Sugarcane ethanol production generates considerable quantities of vinasse, its main wastewater. Microalgae cultivation is a promising option for effluent remediation, since the generated biomass can be feedstock for biofuel and bio-based chemical production. Due to vinasse high turbidity, pretreatment is necessary to clarify this effluent, adapting it as a mixotrophic culture medium. In this context, the present research evaluated the integrated process of electrocoagulation (EC) of sugarcane vinasse with aluminum or iron electrodes and subsequent cultivation of green microalgae Desmodesmus subspicatus. Results indicate pH neutralization and high turbidity removal efficiency by EC with both electrode materials. Aluminum EC and subsequent microalgae cultivation removed 66 and 75% of initial total organic carbon and total nitrogen, respectively, with biomass productivity of 1.45 g L-1day-1 and maximum specific growth rate of 0.095 h-1. Microalgae productivity was inferior in vinasse pretreated by iron EC, suggesting possible interference of ferric compounds in the microalgal development. Resumen La producción de etanol a partir de caña de azúcar genera cantidades considerables de vinaza, su principal agua residual. El cultivo de microalgas es una opción prometedora para su tratamiento, sin embargo es necesaria una clarificación previa. En este contexto, la presente investigación evaluó el proceso de electrocoagulación (EC) de vinaza de caña de azúcar con electrodos de aluminio o hierro y el posterior cultivo de la microalga Desmodesmus subspicatus. Los resultados de la EC indican neutralización de pH y alta remoción de turbidez con ambos electrodos. Se removió el 66 y 75% del carbono orgánico y nitrógeno total, respectivamente, con EC usando electrodos de aluminio y posterior cultivo, con productividad de biomasa de 1,45 g L-1día-1 y velocidad específica de crecimiento máxima de 0,095 h-1. El cultivo en vinaza pre-tratada por EC con electrodos de hierro fue afectado negativamente, posiblemente por interferencia de compuestos del metal con la microalga.
- Published
- 2019
42. No escribirás: leer inscripciones, tocar expedientes y lo sagrado en la Corte Constitucional de Colombia
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Díaz Valderrama, Miller Oswaldo, Ashmore, Malcolm Thomas, Restrepo Forero, Olga Matílde, González, Dahiana (Pepita Ritu), and Estudios Sociales de la Ciencia, la Tecnología Y la Medicina
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Inscripciones ,Corte Constitucional de Colombia ,Sociología organizacional ,Ethnography ,Expedientes ,File of papers bearing on a case ,Lo sagrado ,Tacto ,Etnología ,Touch ,Bureaucracies ,The sacred ,301 - Sociología y antropología [300 - Ciencias sociales] ,Affects ,Organizational sociology ,etnografía ,Burocracias ,Ethnology ,Inscriptions ,Constitutional Court of Colombia ,Afectos - Abstract
ilustraciones, fotografías, gráficas, tablas This thesis deals with the presence of a sacred object in a modern institution. For this, I take a naturally-occurring metaphor seriously, during my ethnographic passage through this institution between August and December of 2019. According to this metaphor, a file is sacred because it is a public document. I ask how a technology of legal knowledge -an inscription- such as the file becomes a sacred object in the hands of its holders. For this, I focus on the practices of touching tutela files in their reviewing. I analyse how the sacred speaks of two different ways of touching and relating with the file: as a working document and as the history of a case. One in which writing and touch are part of the business-as-usual of the Court, and the other in which writing and the touch on files are restricted and forbidden in their circulation. I focus on the transformation of one version of the file into another, in which the Court and the file become a macro actor (a Wholly-other entity), while other actors are absent from their representational practices. Thus, I show how the file organizes the Court and how, in the same movement, it becomes touchy and touching: something delicate that must be protected, being endowed with the risky capacity to record everything in its path. In this, the file is also granted the capacity to touch, producing an emotional witnessing of the Court. Esta tesis se ocupa de un objeto sagrado en una institución moderna. Para esto, tomo en serio una metáfora naturalmente ocurrida durante mi paso etnográfico por la Corte Constitucional entre agosto y diciembre de 2019, según la cual un expediente es sagrado al ser un documento público. Me pregunto cómo una tecnología de conocimiento jurídico -una inscripción- como el expediente se convierte en un objeto sagrado en manos de quienes lo manejan y, para ello, me centro en las prácticas de tocar los expedientes de tutela en su revisión. Analizo cómo lo sagrado habla de dos formas diferentes de tocar y relacionarse con esta tecnología: como documento de trabajo y como historia de un caso. En una de estas, la escritura y el tacto de expedientes forman parte del funcionamiento habitual de la Corte y, en la otra, la escritura y el tacto del expediente están restringidos y prohibidos en su circulación. Me centro en la transformación de una versión del expediente en otra, donde la Corte y el expediente se convierten en un macro actor (uno totalmente-otro), mientras que otros actores son invisibilizados en sus prácticas de representación. Así, muestro cómo el expediente organiza la Corte y cómo, en el mismo movimiento, éste se vuelve sensible y envolvente: algo delicado que debe ser protegido, siendo dotado con la riesgosa capacidad de registrar todo a su paso. En esto, al expediente también le es concedida la capacidad de tocar, produciendo un testimonio emocional de la Corte. (Texto tomado de la fuente). Incluye anexos Maestría Magíster en Estudios Sociales de La Ciencia
- Published
- 2021
43. TRANSMISSÃO VERTICAL DO HIV: REFLEXÕES PARA PROMOÇÃO DA SAÚDE E DO CUIDADO DE ENFERMAGEM
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Deise Maria do Nascimento Sousa, Patrícia Neyva da Costa Pinheiro, Lara Leite de Oliveira, Igor Cordeiro Mendes, Mônica Oliveira Batista Oriá, and Ana Carolina Maria Araújo Chagas
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Cultural Studies ,lcsh:RT1-120 ,lcsh:Nursing ,Transmission (medicine) ,Infectious disease transmission ,Religious studies ,Human immunodeficiency virus (HIV) ,Enfermagem ,Context (language use) ,hiv ,Paper based ,medicine.disease_cause ,Health promotion ,Nursing ,medicine ,Health education ,Disease prevention ,Promoção da Saúde ,Psychology ,Transmissão Vertical de Doença Infecciosa - Abstract
Objective: To reflect about vertical transmission of hiv in the context of health promotion and nursing care.Summary of content: This is a reflection paper based on a literature search of articles and publications for the subject of Ministerio da Saude do Brasil. The following descriptors wereused: Infectious Disease Transmission, Vertical, hiv, Health Promotion and Health Education. Within the context in which health promotion is conceived as disease prevention, there are several nursing interventions involved in the prevention ofvertical transmission of hiv process, encompassing both pre-pregnancy caring for the hiv-positive woman and prenatal, delivery, and postpartum caring for the hiv-exposed child. It was found that educational actions are of vital importance to promotion of health in the context of the vertical transmission of hiv, in as much as they contribute to establish a dialogicalrelation between nurses and hiv-positive women, which aims toempower them.Conclusion: This paper contributes to nurses to reflect about their practice and to carry out care functions in order to promote health of this public in individual, ethical, and effective manner. This sort of care must cover actual health issues ofhiv-positive woman, ensuring them integral, humanized, and determining care, in accordance with their own specific conditions.
- Published
- 2017
44. Biohydrogen production by co-digestion of fruits and vegetable waste and coffee mucilage
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Edilson León Moreno Cárdenas and Arley David Zapata Zapata
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vegetable waste ,Residuos vegetales ,020209 energy ,Biocombustible ,Fermentación ,02 engineering and technology ,010501 environmental sciences ,Horticulture ,01 natural sciences ,lcsh:Agriculture ,Vegetable waste ,0202 electrical engineering, electronic engineering, information engineering ,Bioreactor ,Mucílago de café ,Biohydrogen ,lcsh:Agriculture (General) ,fermentation ,0105 earth and related environmental sciences ,Hydrogen production ,Chemistry ,Coffee mucilage ,lcsh:S ,Substrate (chemistry) ,Forestry ,Pulp and paper industry ,lcsh:S1-972 ,biofuels ,Mucilage ,Biofuel ,Biofuels ,Fermentation ,Animal Science and Zoology ,coffee mucilage ,Agronomy and Crop Science ,Food Science ,Mesophile - Abstract
In the present investigation, the effects of the substrate composition, organic load, medium acidification time, operation pH, and temperature on the production of hydrogen by anaerobic fermentation with fruits and vegetable waste, and fresh mucilage of coffee was evaluated. For this purpose, tests were carried out in a 20-liter bioreactor operated in batch mode, under a central composite experimental design (CCD). The fermentations were conducted under mesophilic conditions, without adding inoculum, and without sterilizing the substrate. The results for maximum daily hydrogen production (MDP), the maximum hydrogen content in the gas (MHC) and cumulative production (CHP) showed an acceptable fit to second-order polynomial models. All the independent variables were significant, especially the operation pH and the acidification time. Also, the premises for a model obtained by regression, according to an error analysis, were fulfilled. In the same way, it was possible to optimize the response variables. The maximum specific production concerning the organic load was 5511 mL H2 gCODremoved -1, and regarding the volatile solids was of 670 mL H2 gVSadded -1. These values are higher than those reported with similar substrates in continuous fermentation, with cell retention, use of inoculum, and substrate pretreatment. RESUMEN En la presente investigación se evaluó el efecto de la composición del sustrato, carga orgánica, tiempo de acidificación del medio, pH de operación y temperatura sobre la producción de hidrógeno por fermentación anaerobia de residuos de frutas, verduras y mucílago fresco de café. Para ello se realizaron pruebas en un bioreactor de 20 L operado en modo batch, bajo un diseño experimental de composición central (CCD). Las fermentaciones fueron realizadas en condiciones mesofílicas, sin adición de inóculo y sin esterilizar el sustrato. Los resultados en la producción diaria máxima de hidrógeno (MDP), contenido máximo de hidrógeno en el gas (MHC) y producción acumulada (CHP), presentaron ajuste aceptable a modelos polinomiales de orden dos. Todas las variables independientes fueron significativas, destacándose el pH de operación y el tiempo bajo condiciones ácidas, además se cumplieron las premisas para un modelo obtenido por regresión, según un análisis del error. De igual manera fue posible optimizar las variables de respuesta. La máxima producción específica respecto a la carga orgánica fue 5511 mLH2 gDQOremovido -1 y frente a los sólidos volátiles fue 670 mL H2 gVSadicionado -1, valores superiores a los reportados con sustratos similares en fermentaciones continuas, con retención de células, uso de inóculo y pretratamiento del sustrato.
- Published
- 2019
45. Codigestión de estiércol de bovino y residuo de poda para la producción de biogás mediante digestión anaerobia con agitación a escala laboratorio
- Author
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Andrea Lache, Yesica Dayana Giraldo, Adriana Inés Paéz, and María Alejandra Ortíz
- Subjects
lcsh:GE1-350 ,Residual biomass ,Chemistry ,020209 energy ,lcsh:Geography. Anthropology. Recreation ,agitación ,digestión anaerobia ,02 engineering and technology ,010501 environmental sciences ,Pulp and paper industry ,01 natural sciences ,Manure ,Anaerobic digestion ,reactor uasb ,lcsh:G ,Biogas ,Thermal isolation ,codigestión ,biogás ,0202 electrical engineering, electronic engineering, information engineering ,biomasa residual ,Environmental energy ,Cow dung ,lcsh:Environmental sciences ,0105 earth and related environmental sciences - Abstract
The implementation of new processes for the use of residual biomass is one of the intrinsic goals in the goals established within the objectives of sustainable development to contribute to environmental energy security. This article deals with the production of biogas by co-digestion of bovine waste and bovine manure in two UASB reactors with the same dimensions, with thermal isolation system and without external heating and an average temperature of 16°C, differentiated only because one of them incorporated a manual agitation system. The mixture of pruning residue and cow manure was made with a 1: 2 ratios, a pH of 6.24 and 7.3 (respectively) and a humidity greater than 60%. During the process, it was possible to observe the acidification of the reactor without agitation, which inhibited the production of biogas, while in the system with agitation until day 90, produced 11 L of biogas with a methane composition of 21.11%, which showed the favorable effect of agitation on the anaerobic digestion process.
- Published
- 2019
46. Incidence of operative parameters in the production of biohydrogen generated from urban organic waste
- Author
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Deisy Yuliana Cano Quintero and Edilson León Moreno-Cárdenas
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Optimization ,Renewable energy ,Hydrogen ,chemistry.chemical_element ,Fermentación ,Energía renovable ,02 engineering and technology ,010501 environmental sciences ,Horticulture ,Optimización ,Materia orgánica ,Stirring ,01 natural sciences ,lcsh:Agriculture ,Bioreactor ,Biohydrogen ,Organic matter ,lcsh:Agriculture (General) ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Acidification stage ,Etapa de acidificación ,Daily production ,Chemistry ,lcsh:S ,Forestry ,Hydrogen content ,Biodegradable waste ,021001 nanoscience & nanotechnology ,Pulp and paper industry ,lcsh:S1-972 ,Fermentation ,Animal Science and Zoology ,Agitación ,0210 nano-technology ,Agronomy and Crop Science ,Food Science - Abstract
Organic waste is considered a substrate of great interest to produce biohydrogen. In the present work, the influence of some physical and chemical parameters in the operation of a bioreactor for biohydrogen generation were studied, taking as a substrate organic residue from a wholesale food market without adding inoculum. Therefore, an experimental design of central composition was made, with four factors and two levels. The dependent variables were maximum hydrogen content (% of H2), daily production of hydrogen (L H2 d-1) and its cumulative production (L H2). The independent variables were operation pH (pHo), pH of acidification (pHa), the duration time of the acidification stage, and stirring. A numerical optimization was carried out, allowing the prioritization of the factors, and maximizing the response variables. Resulting in a yield of up to 14.9 L H2 d-1, a hydrogen content of 49.2% and a cumulative production of 21.6 L H2, for pHa values of 4.9; pHo between 6 and 6.1; acidification time of 2 d and stirring of 41.4 rpm. Likewise, a graphical optimization was carried out, reaching 14.9 L H2 d-1, a hydrogen content of 44.2% and an accumulated 22.8 L H2, for pHa values between 4.5 and 4.95; pHo between 5.6 and 6.3; acidification time of 2 d, and stirring of 37.1 rpm. Maximum yields were 1.9 L H2 Lwaste.day -1, 4800 mL H2 gCOD -1, and 608.6 m L H2 gTVSadded -1, values similar to those reported by other authors using organic waste in the production of hydrogen, using inoculum. RESUMEN Los residuos orgánicos son considerados sustratos de gran interés para la producción de biohidrógeno. En el presente trabajo se estudió la influencia de algunos parámetros físicos y químicos en la operación de un bioreactor para la generación de biohidrógeno, tomando como sustrato residuos orgánicos provenientes de una central de abasto sin adicionar inóculo. Para ello se realizó un diseño experimental de composición central, con cuatro factores y dos niveles. Las variables dependientes fueron el contenido máximo de hidrógeno (% de H2), la producción diaria de hidrógeno (L H2 d-1) y su producción acumulada (L H2). Las variables independientes fueron, pH de operación (pHo), pH de acidificación (pHa), tiempo de duración de la etapa de acidificación y agitación. Se realizó una optimización numérica que permitió priorizar los factores y maximizar las variables de respuesta, obteniéndose hasta 14,9 L H2 d-1, contenido de hidrógeno de 49,2% y una producción acumulada de 21,6 L H2, para valores de pHa de 4,9; pHo entre 6 y 6,1; tiempo de acidificación de 2 d y agitación de 41,4 rpm. De igual forma se realizó una optimización gráfica alcanzándose 14,9 L H2 d-1, un contenido de hidrógeno de 44,2% y 22,8 L H2 acumulado, para valores de pHa entre 4,5 y 4,95; pHo entre 5,6 y 6,3; tiempo de acidificación de 2 d y agitación de 37,1 rpm. Los rendimientos máximos fueron de 1,9 L H2 Lresiduo.día -1, 4800 mL H2 gDQO -1 y 608,6 mL H2 gSVadicionado -1, valores similares a los reportados por otros autores empleando residuos orgánicos en la producción de hidrógeno usando inóculo.
- Published
- 2019
47. Análisis de la eficiencia de reactores UASB en una planta de tratamiento de aguas residuales municipales
- Author
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Carlos Alfonso Zafra Mejía, Ludwing Uribe García, Luisa Marina Gómez Torres, and Luis Salazar Larrota
- Subjects
lcsh:TN1-997 ,Biochemical oxygen demand ,water pollution ,Suspended solids ,Hydraulic retention time ,lcsh:T ,UASB reactors ,Chemical oxygen demand ,General Engineering ,chemistry.chemical_element ,reactores UASB ,Pulp and paper industry ,tratamiento anaeróbico ,lcsh:Technology ,Nitrogen ,Methane ,municipal wastewater ,contaminación del agua ,Anaerobic digestion ,chemistry.chemical_compound ,aguas residuales municipales ,chemistry ,Wastewater ,anaerobic treatment ,lcsh:Mining engineering. Metallurgy - Abstract
Resumen Se evaluó la eficiencia de los reactores UASB (Upflow Anaerobic Sludge Blanket) en una planta de tratamiento de aguas residuales (PTAR) municipales durante un periodo de 9 años. La PTAR trató un caudal promedio de 500 l/s, con eficiencias de remoción de demanda bioquímica de oxigeno (DBO5), demanda química de oxigeno (DQO) y sólidos suspendidos (SS) de 66 %, 52 % y 60 %, respectivamente. La producción de biogás alcanzó 37541 m3/mes (82.4% de metano), y con una producción de lodo de 334 m3/mes. El tiempo de retención hidráulico estuvo entre 7 y 8 horas, intervalo típico de sistemas UASB para una temperatura de 26 °C. No se encontró remoción de nitrógeno y fósforo. Las eficiencias, y resultados similares en Indonesia y América Latina, sirvieron para concluir que la digestión anaeróbica fue un proceso promisorio para el pretratamiento de aguas residuales en países tropicales. Abstract The UASB (Upflow Anaerobic Sludge Blanket) reactors efficiency of a municipal wastewater treatment plant (WWPT) was evaluated over a period of 9 years. The WWTP treated an average flow of 500 l/s, with removal efficiencies of biochemical oxygen demand (BOD5), chemical oxygen demand (COD), and suspended solids (SS) of 66 %, 52 %, and 60 %, respectively. The biogas production reached 37541 m3/month (82.4 % of methane), with a sludge production of 334 m3/month. The hydraulic retention time was among 7 and 8 hours, typical interval of UASB systems for a temperature of 26 °C. Removal of nitrogen and phosphorous was not found. The efficiencies, and similar results in Indonesia and Latin America, served to conclude that anaerobic digestion was a promising process for the pretreatment of wastewater in tropical countries.
- Published
- 2019
48. Evaluación del quitosano como coagulante para el tratamiento de efluentes piscícolas
- Author
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Dalia Milena Rodriguez Jimenez and Darío Gallego Suárez
- Subjects
Flocculation ,Chemistry ,prueba de jarras ,biopolymers ,General Medicine ,jar test ,Pulp and paper industry ,Chitosan ,chemistry.chemical_compound ,effluent clarification ,clarificación de efluentes ,Volatile suspended solids ,biopolímeros ,Coagulation (water treatment) ,Sewage treatment ,Turbidity ,Effluent ,TP248.13-248.65 ,Biotechnology ,Total suspended solids - Abstract
RESUMEN El uso de polímeros orgánicos para el tratamiento de aguas residuales a través de procesos de coagulación/floculación presenta ventajas sobre el uso de coagulantes inorgánicos, debido a la biodegradabilidad y la baja toxicidad en el agua de estos. El quitosano es un biopolímero que se ha utilizado como coagulante en el tratamiento de aguas residuales. En este estudio, se evaluó el quitosano como coagulante natural utilizado en la clarificación de efluentes piscícolas en tecnología biofloc (BFT) y en sistema de recirculación acuícola (RAS). Se implementó un diseño experimental completamente aleatorizado, de una vía, con efectos fijos. Los ensayos del agua se llevaron a cabo por el método de jar-test, donde se aplicaron dosis de quitosano de 3, 6, 9, 12 y 15 mg/L. Se analizó el efecto estadístico de la dosis de quitosano en la eliminación de la turbidez, sólidos suspendidos totales (SST) y sólidos suspendidos volátiles (SSV) del agua. Se encontró efecto del quitosano sobre la turbidez, dosis de 9 mg/L logró remociones del 88% y valores de 3.9 NTU (con error < 0.05). Sin aplicar quitosano al efluente, se lograron remociones de 78.2 y 76.7% para SST, SSV respectivamente. El quitosano permitió eliminar turbidez del efluente (BFT). ABSTRACT Using organic polymers for wastewater treatment through coagulation/flocculation processes is more advantageous than current approach based on inorganic coagulants, due to the former's biodegradability and low toxicity in the water. Chitosan is a biopolymer that has been used as coagulant in wastewater treatment. In this study, chitosan was evaluated as a natural coagulant used in the clarification of fish effluents in biofloc technology (BFT) and aquaculture recirculation system (RAS). A one-way completely randomized experimental design with fixed effects was implemented. The water clarification tests were conducted using the jar test method with chitosan doses of 3, 6, 9, 12 and 15 mg/L. The chitosan dose effect was analyzed as natural coagulant on the removal of the water's turbidity, total suspended solids (SST) and volatile suspended solids (SSV). The effect of the chitosan load on the turbidity removal was found, as optimal dose of 9 mg/L for 88% with final turbidity value of 3.9 NTU (with significance < 0.05). In absence of chitosan, only values of 78.2 and 76.7% for SST and SSV were reached, respectively. Chitosan allowed the removal of turbidity from the water (BFT).
- Published
- 2019
49. Estudio inicial de Ceniza de Madera de Eucalipto (CME) como aditivo mineral en concreto
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Nicole Schwantes-Cezario, Álisson Franco do Couto, Geovana Souza Ferreira Nogueira, Gersson F.B. Sandoval, and Gilson Morales
- Subjects
caracterización ,lcsh:TN1-997 ,carbonato de calcio ,020209 energy ,0211 other engineering and technologies ,02 engineering and technology ,engineering.material ,lcsh:Technology ,chemistry.chemical_compound ,compressive strength ,Specific surface area ,Filler (materials) ,021105 building & construction ,0202 electrical engineering, electronic engineering, information engineering ,Organic matter ,resistencia a la compresión ,calcium carbonate ,characterization ,lcsh:Mining engineering. Metallurgy ,chemistry.chemical_classification ,Cement ,lcsh:T ,filler ,General Engineering ,Wood ash ,Pozzolan ,Pulp and paper industry ,concreto ,Calcium carbonate ,chemistry ,engineering ,Environmental science ,concrete ,Specific gravity - Abstract
This study evaluated the possibility of using in natura Eucalyptus Wood Ash (EWA) from aviary furnaces as a mineral admixture in concrete. The ash was 100 mesh-sieved and added to the mix in 5, 10, 15 and 20% of the cement bulk. Physical analysis unveiled that EWA has a specific gravity higher than other organic originated residues, whereas its BET specific surface area is not enough to enhance its filler and/or pozzolanic effects. Chemically, the residue presented a low organic matter rate and a SAI below the minimum required by the Brazilian standards. EWA interfered in the times of cement set, increasing them, while FTIR unveiled mainly the presence of calcium carbonate bonds. The admixture compromised the concretes mechanical performance, leading to the conclusion that the sieving procedure of EWA alone is not enough do admit its usage as a mineral admixture. Resumen Este estudio evaluó la posibilidad de usar Ceniza de Madera de Eucalipto (CME) de hornos de aviarios como un aditivo mineral en la fabricación de concreto. La ceniza fue pasada por el tamiz número 100 y se adiciono a la mezcla en la proporción 5, 10, 15 y 20% de la masa del cemento. El análisis físico reveló que la CME tiene una masa específica mayor que otros residuos de naturaleza orgánica y su área superficial específica BET no es suficiente para mejorar sus efectos filler y/o puzolánico. Químicamente, el residuo presentó un bajo porcentaje de materia orgánica y un IAP inferior al mínimo requerido por la norma brasileña. La CME interfirió en los tiempos de fraguado del cemento, aumentándolo, mientras la FTIR reveló la presencia de enlaces de silicio-oxígeno y carbonato de calcio. El aditivo comprometió el rendimiento mecánico de los concretos, concluyéndose que el procedimiento de tamizado de la CME solo no es suficiente para su uso como un aditivo mineral.
- Published
- 2019
50. Co- digestión anaerobia de la fracción orgánica de residuos sólidos urbanos y su lixiviado
- Author
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Mabelin Benitez Fonseca, Arelis Abalos Rodríguez, and Suyén Rodríguez Pérez
- Subjects
0106 biological sciences ,education.field_of_study ,Municipal solid waste ,Chemistry ,lixiviados ,Batch reactor ,Population ,remoción de sólidos ,General Medicine ,010501 environmental sciences ,Pulp and paper industry ,01 natural sciences ,Total solid content ,Anaerobic digestion ,010608 biotechnology ,Tratamiento anaerobic ,Leachate ,education ,co-digestión ,Anaerobic exercise ,Cow dung ,lecho escurrido ,TP248.13-248.65 ,0105 earth and related environmental sciences ,Biotechnology - Abstract
Los residuos sólidos urbanos (RSU), al ser vertidos sin tratamiento adecuado, ocasionan daños severos al ambiente influyendo en la calidad de vida de la población, razón por la cual actualmente se le presta atención diferenciada al vertido de residuos urbanos. En este trabajo se evalúa la fracción orgánica de estos residuos (FORSU), tomando como referencia el grupo poblacional de una de las Residencias estudiantiles de la Universidad de Oriente. La generación de FORSU en la residencia es de 0,06 kg/hab/día, con un contenido de sólidos totales de 30,9 ± 5,3 % de los cuáles el 81,7 ± 0,6 % son sólidos volátiles. Se evalúa el funcionamiento de un reactor en lote de lecho escurrido, que permitió un tratamiento discontinuo e in situ de la FORSU, en codigestión anaerobia con un 25 % de estiércol vacuno en una primera etapa. También se evalúa, en una segunda etapa, el tratamiento anaerobio para los lixiviados que se generan en el reactor en lote, empleando un reactor UASB. En el reactor en lote se alcanzó una remoción de sólidos volátiles del 44,1 %, mientras que en el reactor UASB se removió un 81,2 % de DQO. Como resultado del sistema de tratamiento evaluado, se alcanzó una productividad total de 5,37 LCH4·kgSV-1·d-1.
- Published
- 2020
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